In a color image device or color image processing system, the image qualities of color images are an extremely important factor. Therefore, careful setting is necessary for the image quality of color images realized by the color image device or color image processing system. Here, the focus is put on such image qualities as brightness of an entire image, gamma characteristics, and sharpness, which can be arbitrarily adjusted by image processing, not on such image qualities as the physically determined limit values of white or black in brightness or density and the color gamut of devices, which are attributable to hardware characteristics. The image qualities represent the capability and characteristics of the color image device or color image processing system. Therefore, setting of the image qualities is an extremely important factor.
Now the setting of such image qualities is performed primarily based on the detailed evaluation and adjustment of image qualities by engineers. According to the method, the image qualities set in the color image device or color image system are mostly affected by the skill (capability) of a person who makes sure of the image qualities of color images in the color image device or color image system to adjust the image qualities. That is, in the color image device or color image processing system, an engineer who has a high capability in adjusting image qualities is required in order to appropriately stabilize the image qualities as expected.
These days, various kinds of color image devices, such as PDP (Plasma Display Panel), LCD (Liquid Crystal Display), printers, camera-equipped cellular phones, and projectors, are put into the market. When just one component used to form an image is replaced in a device, the image qualities change. Therefore, the adjustment of image qualities is performed each time the component is replaced. Moreover, even if the configuration of components is the same, the image qualities to be expressed may change according to type of device. Even if the type of device is the same, there may be a plurality of image quality modes. In each case, the adjustment of image qualities is necessary.
A completely automated method for adjustment or setting of image qualities or designing thereof has not yet been realized. Therefore, in order to put various kinds of such color image devices into the market, it is necessary to have many engineers who have high capabilities in adjusting image qualities. However, it takes enormous time and efforts to improve people's image quality adjustment capabilities because the technique is learned through the actual work of adjusting image qualities. Accordingly, it is effectively impossible to gather many engineers who have high capabilities in adjusting image qualities in a short period of time. Therefore, the adjustment of image qualities of color image devices, the various types of which are increasingly put into the market, is currently performed by a small number of engineers who spend much energy and production processes for the adjustment.
The following Patent Documents 1 and 2 disclose conventional arts related to the above-described image processing.
Patent Document 1 proposes an image processing device that includes an input section, an instructor data extraction section, a correction section, and an image processing section in order to intuitively and easily convey favorite image reproduction to the image processing device so that the favorite image reproduction is reflected in the image process. The image processing device operates in the following manner: The input section accepts the input instruction of a target image (an instructor image) for image reproduction in the image process; the instructor data extraction section performs analysis or information collection for the predetermined image reproduction items for the instructor image provided, and extracts instructor data representing the tendency of image reproduction; the correction section corrects parameters of the image process in accordance with the tendency of image reproduction represented by the instructor data; the image processing section performs the image process for the input image using the corrected parameters.
Patent Document 2 proposes an image processing device that includes a preliminary correction section, an amount-of-characteristic calculation section, a correction value calculation section, and a correction execution section in order to efficiently perform image qualities of the corrected image of each image among a group of images. The image processing device operates in the following manner: The preliminary correction section preliminarily corrects a sample image among a group of images and obtains the preliminarily corrected image of the sample image; the amount-of-characteristic calculation section calculates the amount of characteristic of each preliminarily corrected image; the target-amount-of-characteristic calculation section calculates the target amount of characteristic such that the variation between the target amount of characteristic and the amount of characteristic of each preliminarily corrected image is minimized; the correction value calculation section calculates a correction value of each image such that the amount of characteristic of each image of the group of images is equal to the target amount of characteristic; the correction execution section uses the correction value to correct the corresponding image.
Patent Document 1: JP-A-2006-080746
Patent Document 2: JP-A-2006-139368
Non-Patent Document 1: Masato Tsukada, Tetsuaki Suzuki, and Akira Inoue, “Automated technique for improving image qualities in digital image processing”, Journal of the Imaging Society of Japan, 2004, Vol. 43, No. 2, pp. 90-97